[3] SquirrelMail webmail outputs valid HTML 4.0 for its presentation, making it compatible with a majority of current web browsers.

SquirrelMail webmail was included in the repositories of many major Linux distributions[6][7][8][9][10][11][12][13][14] and is independently downloaded by thousands of people every month.

SquirrelMail IMAP Proxy compiles on most flavors of Unix, and can generally be used on the same platforms that the webmail product can with the exception of Microsoft Windows, unless used in a Cygwin or similar environment.

[2] SquirrelMail has been implemented as the official email system of the Prime Minister's Office of the Republic of India for its security advantages over Microsoft's Outlook Express.

[17][18][19][20] In 2004 HEC Montréal business school deployed SquirrelMail as part of a comprehensive webmail solution, to support thousands of users.